Voice-recording apparatus



May '27, 3930. 1,. s QNE, JR

VOICE RECORDING APPARATUS Filed Feb, 4 20, 1928 gr mxm lfo'o lax name: 570/145; J2

Patented May 27, 1930 UNITED STATES LAWRENCE STONE, .13., or nnnvnn, COLORADO voron-nnoonnme AIPARATUS Application filed February 20, 1928. Serial No. 255,751.

This invention relates to'a device for receiving, amplifying and recording sounds, and has for its principal object, the provision of an efficient portable mechanism which can be employed to record conversations. and remarks of supposed criminals for use in court proceedings.

At present suspected parties under arrest will often make a confession of'a crime to the 1 arresting authorities. Later they will repudiate this confession and state that it either was not made at all, or that it was obtained by force, threats, duress, etc. With the use of this machine the court can later hear a reproduction of the entire confession proceedings with the natural voice of the prisoner and all questions and statements which were made to him so that the authenticity of the confession can be quickly determined.

Another object of the invention is to so construct the device that it can be used without the knowledge of the persons Whose voices are being recorded.

A further object of the invention is to provide a device for recording the proceedings in a courtroom for the useof the attorneys in preparing their 'cases for the next 'day. At present it is often impossible for thecourt stenographer to be able to deliver a copy of the testimonyin time for it to be of use to the attorneys in preparing'their following procedure. With the use of the invention, the entire days proceedings can be reproduced by the attorneys immediately after the close of the days session.

Still another object of the invention is to provide means whereby the slightest whisper can be built 11 in volume until it is audible and deciphera le.

Still another object is to provide a portable mechanism which can be connected with the microphone systems at present in use in 'ails and the like, so that the conversation o the prisoners can be placed on a. permanent authentic record.

Many otheruses for the invention will appear such as recording and reproducing a speech delivered by telephone or radio re cording; recording the ante-'mortem stateinnts or dying declarations; transmitting news to newspaper offices over wire circuits; and recording the news for radio use, etc.

Other objects and advantages reside in the construction of the invention and in its use. These will become more apparent from the following detail description and are to be understood as contemplated by this invention. In the following detailed description of the invention reference is bad to the accompanying drawing which forms a parthereof. Like v I numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing: Fig. 1 is a perspective View of the apparatus assembled for recording sound from-,a

microphone circuit.

Fig. 2 is a .perspective view of the apparatus used for transmittingythe vibrations of the recorder to the ampli ing-unit.

Fig. 3 is a circuit diagram illustrating the'7o electrical apparatus and connections em-' ployed.

The entire apparatus is contained within a suitcase-like container 10 having a lid 11.

The container 10 is divided into, compart- 76 ments designated by numerals as follows: amplifying compartment 12, recording compartment 13, A battery compartments 14:, B battery compartments 15 and spare rec- 0rd compartment 16. The amplifying com- 80 partment 12 and the battery compartments Hand 15 are covered by suitable plates 17.

I The recording portion of the apparatus may be of any of the usual record recorders which'are designed to rotate an impressionable record, upon which, sound vibrations leave-indentations and having a combined recording and reproducing mechanism. The apparatus for rotating the record is illustrated at 18, the record at 19,, and the needle holder or reproducer and recorder at'20.

' Broadly speaking, the sounds are electrically received by the amplifying portion of thedevice from any desired source such as a telephone circuit, a microphone, radio receiving apparatus, etc. These sounds may be amplified electrically, if necessary, in the amplifying portion of the apparatus and are then transmitted through a plug 21, cable 22, and a reproducer 23. The reproducer is designed to be detachably attached to the retensity, that their reproduction from the record cannot be deciphered. In such a case, I employ the apparatus illustrated in Fig. 2

comprising a microphone 24 having a sleeve or other suitable connection 25 for attach-- ing it to the reproducer and recorder 20. The microphone is connected to plugs 26 by means of a suitable cord 27. By placin the microphone 24 in the place of the repro ucer 23 and connecting the plugs 26 to the intake of the amplifying unit I can build up these sounds to any desired intensity in the amplifying unit so that they will become decipherable. Should it be impossible to decipher the sounds after amplification they may be transmitted to a second recording mechanism and in their amplified condition and recorded on a second record. The sounds from this record can then be amplified. This process can be carried out indefinitely so that the slightest whisper can be built up to the desired volume.

The amplifying circuits are illustrated in diagram in Fig. 3 and comprise a series of audio-tubes 28 connected through audio-stepup transformers 29. It will not be necessary to describe in detail the audio amplifying .circuits since these'ma-y be similar to any de sired audio-amplifying hook-up. The electric impulses to be am lified are fed into the amplifying hook-up t rough input leads 30 and the amplified electric impulses flow from the amplifying hook-up through output leads 31.

In the diagram the Albattery is indicated at 32, B battery at 33 and C battery 34. The output leads 31 lead .to a jack 35 designed to receive the plug 21. This jack is of the double contact type so that it will cause a pair of contacts 36 to close the A battery circuit so as to furnish current to the tube filaments wherever the plug isinserted for use. 1

The output leads 31 also are connected by means of conductors 37 to a'pair of plugs 38 marked, 2nd stage, upon the cover of the amplifiyingcompartment 12. The conductors 37 also lead through a rheostat 59 to a loud speaker unit 39 to which a horn may be attached. Thus the amplifiedsounds can be taken out of the jack 35 to the record 23, also out of the receptacles 38 to a head set or similar apparatus and also can be heard from the horn 60. I

By this arrangement the operator can listen in upon a conversation being recorded upon the record or can ,cut out the recordin portion of the device and make a record 0 the conversation ste'nographically either from a head set or from the horn 60. The rheostat 59 is operable from above the cover of theamplifying. compartment so as to control the volume of sound in the horn 60 or disconnect it entirely.

The input leads 30 connect with the secondary of an induction coil 40. The primary of the induction coil 40 receives its current through conductors 41 which connectwith a pair of plug receptacles 42 marked, telephone, and a second pair of plug receptacles 43 marked 1st stage. tions from the electrical sources are fed into the amplifying unit through a pair of plug receptacles, 44, marked detector, which connect through suitable conductors 45 which conduct the current through the batteries to the input leads 30.

The input from the receptacles 44 is controlled'by a rheostat 46. A second rheostat 47 is provided onthe input leads. Switches 48 may be used to break the secondary circuit to the induction coil 40- Thus, the volume of sound can be controlled through the rheostats 59, 46, and 47 by means of the switches 48. If one of the switches 48 is opened, the circuit continues through the break because of capacitative coupling, thus reducing the sound volume. may be further reduced by opening the other switch 48, so that the entire circuit is inmans voice Will come in with such volume as'to be uncomfortable. I provide for this by bridging a condenser 50 between the input leads 30. This condenser can be temporarily placed in circuit'by means of a switch 52; \Vith this arrangement the operator can-keep his finger on the press button and when the man speaks he can depress this button so as to reduce the sound volume. As is usual in installationsof this character, a voltmeter 53 is provided which can be placed incircuit with the A battery by means of a switch 54 and with the B battery by meansof a switch 55 so as to test the battery voltage. The entire battery current can be disconnected from the device by means of a main switch '56.

This volume The electric vibrabe recorded, as amplified, upon the record 19, or listened to through a head set plugged into the 2nd stage receptacles 38 or from the loudspeaker horn 60.

'If it is desired to connect the apparatus to a telephone circuit, such as a jail telephone system to listen to or record a telephone conversation, conductors from the telephone cir-- cuit are plugged into the telephone recep m tacles 42 and the sounds can be recorded or listened to as previously described. Should the operator also desire to listento the natural telephone conversation he can plug his head set into the 1st stage receptac es 43,

15 from which, he will hear the sound unamplified. The leads from the radio set can also be plugged into either the detector, or telephone receptacles for recording a program or radio lecture.

A plug receptacle 58 is provided through whichcurrent is fed to the motor for operatin the recorder mechanism 18.

t is desired to be understood that the batteries may be entirely eliminated and the device operated from the electric light circuit by the use of suitable battery eliminators. The amplifying unit is not limited to any particular number of stages.

While a specific form of the improvement has been described and illustrated herein, it

said container dividing the latter into compartments; and electrical amplifying unit in one of said compartments; a panel covering said latter. compartment; an electrical sound producin unit supported by said panel; a born a apted to be connected with said latter unit; a first connector extending through said panel; a microphone adapted to be detachably connected with said first connector; a circuit between said first connector o/and the input of said amplifying means so that said microphone will impress impulseson said amplifying unit; an electrical recording apparatus earned in another one of said compartments a second connector extending through said' panel; a second circuit between said second connector and the output of said amplifying unit; a third circuit between said sound producing unit and the output 0" said amplifying unit; detachable means for connecting said recording apparatuswith said second connector; and means on said panel paratus in circuit with the output of said amplifying unit.

2. A combined sound reproducer and recorder comprising a container; partitions in said container dividing the latter'into compartments; an'electrical amplifying unit in one of said compartments; a panel coveringsaid-latter compartment; an electrical sound producing unit supported by said panel; a horn adapted to be connected with said latter unit; a first connector extending through said panel; a microphone adapted to be detachably connected with said first connector; a circuit between saidfirst connector and the input of said amplifying means so that said microhone will impress im ulses on said ampliying unit; an electrical recording apparatus carried in another one of said compartments;

a second connector extending through said panel; a second circuit between said second connector and the output of said amplifying unit; a third circuit between said sound producing unit and the output of said amplifying unit; detachable means for connecting said recording apparatus with said second connector; means on said panel for selectively closing said second and third circuits so as to place either or both said sound producing unit and said recording apparatus in circuit with the output of said. amplifying unit; a reproducer arranged for operation with said recording apparatus and means for selectively placing either said reproducer in circuit with said first connector or said recording apparatus in circuit with said second connector so that said amplifying unit can be selectively used to either amplify vibrations flowing to said recording apparatus or from said re roducer as desired. I 'n testimony whereof, I aflix my signature. LAWRENCE STONE, J R.

for selectively closing said second and third circuits so as to place either or both said 05 sound producing unit and said recordin ap; 

